Popular Astronomy

November 2014

This reporting period began with Michael Kinns sending in two drawings of observations he made using his 200mm f6 Newtonian telescope.

Below left is NGC7142, and on the right NGC7510, both open clusters in the constellation of Cepheus.  Michael used a magnification of 67x for NGC7142, which is near to the reflection nebula NGC7129; studies have shown that the light from the stars in this cluster is reddened, indicating that interstellar matter is partly obscuring it.  Michael noted that "only a few 12th magnitude stars could be resolved among a nebulous background of 13th magnitude stars extending to ~ 9' in an approximate circle".

    NGC7510 was observed at 150x, and the light from this cluster has also undergone extinction from interstellar gas and dust.  This cluster is in the Perseus spral arm.           


Dale Holt sent in drawings of 5 galaxies this month, all observed with a 505mm Newtonian telescope and a Watec120Ncooled video camera.

  Below left is a sketch of NGC1 and NGC2, in the constellation of Pegasus.  

     NGC1 is a magnitude 13.6 spiral galaxy about 190 million light years from the Earth.  NGC2, also a spiral, is fainter still at magnitude 15, and is considerably further away at around 316 million light years.







Below left is a drawing of NGC16, and beside it on the right NGC23, both in the constellation of Pegasus.  NGC16 is magnitude 13.0, whereas NGC23 is magnitude 11.9. 




  Dale's final sketch this month is NGC3432, number 206 in the Arp catalogue of so called peculiar galaxies, by Halton Arp, published in 1966. Magnitude 11.7 NGC3432 is interacting with smaller galaxy UGC5983, shown in the sketch at the upper right, which is much fainter at magnitude 17.0.



     Mike Wood made three observations this month,  using a Takahshi 180mm Mewlon telecope (Dall - Kirkham design).                                                                                                                                                                                                                                                                                           

This drawing (left) is of almost edge - on spiral galaxy NGC2683, which can be found in the constellation of Lynx.  At magnitude 10.6, this galaxy is about 25 million light years from he Earth, and has an angular size of 9.3' x 2.2'.  Magnification used was 73x. 



Mike's second drawing (below left) is the multple star 14 Aurigae, a 5th magnitude star with 3 companions of magnitudes  8.0, 10.4 and 11.0   The three brightest stars are of spectral type A9, A2 and B respectively.        

The third drawing (below right) is a double star designated BU536 which is in the open cluster M45, perhaps better known as the Pleiades. Mike describes it as an "orange pair".                                     



   SPA Planetary Director Alan Clitherow sent in 4 images, 3 emission nebulae plus an open cluster.  The two images below were taken using an Orion ED80 refractor and a QHY10 colour camera.  On the left is IC1805, the HeartNebula in Cassiopeia, and on the right M45, the Pleiades, in Taurus.     


Alan's next two images were taken with the same camera as above, but a smaller telescope;  a Williams Optics 66mm refractor fitted with a 0.8 focal reducer.  Below left is NGC7000, also known as the North America Nebula, an emission nebula in the constellation of Cygnus.  Below right is an image of the Bubble nebula area, also an HII emision region, NGC7635, in Cassiopeia. 




   Mark Beveridge sent in 7 images, all taken using a 100mm f 9 Skywatcher refractor and a SXR-H9c colour camera.  The first two below are galaxies in the constellation of Ursa Major.  On the left is M81, also known as Bode's galaxy, and on the right M103.  M81 is relatively large (26.9' x 14.1') and bright (magnitude 6.9).  M108 appears considerably smaller (8.7' x 2.2'),  and at about 46 million light years is about 4 times more distant than M81.


  Mark.s next two images below are both of the Flame nebula in Orion, NGC2024.  Close to Alnitak in Orion's belt, fierce UV radiation is ionising hydrogen gas.  Cold gas and dust between us and the emission nebula gives rise to the dark lanes that appear to be at the centre.   The brighter of the two images was binned 2 x 2.

                                                                                                                                                                                                                                                                                                                                                                                  Below left is an image of NGCC891, a magnitude 10.8 edge - on galaxy in the constellation of Andromeda. The central dust lane is clearly visible.  On the right is face - on galaxy M74 in Pisces, which is magnitude 10.0 but in reality a more difficult target.  M74, being face - on, has a low surface brightness, its light is spread over a much larger area and for that reason is hard to see at the eyepiece of a telescope, and also more difficult to image.


                                                                                                                                                                                                            The final image sent in by Mark is a black and white image of The Horsehead Nebula, IC434, in the constellation of Orion. This is close to star Alnitak, and the Flame nebula, described  above.



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